This paper presents the results of an experimental investigation of ac gas display panel parameters. The ignition and extinction voltages were measured for panels filled with Ne-0.1% Ar gas to pressures ranging from 0.75×104Pa to 8×104Pa (50 torr to 600 torr). The panels were constructed with chamber spacings, d, of 0.56×10-2cm to 2×10-2cm, and electrode widths, x, of 1.5×10-3cm to 0.1 cm. Scaling of the Paschen minimum was not found to hold for the narrowest chamber spacing. The dependence of ignition voltage on linewidth was found to be proportional to exp(-1.6 x/d) for (x/d)<1. An electron diffusion process was invoked to explain this behavior.